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Jan. 25, 2012 -- Working 11-hour days may seem the norm in this economy, but regularly logging long hours can more than double a worker’s risk of depression.

People who routinely put in more than 11-hour days more than double their chances of major depression, compared to employees who typically work about eight hours a day, a new study suggests.

Long workdays take a physical toll on the body, but there's been mixed evidence of their effects on the brain. And little is known about the link between long work hours and depression.

This research looked at more than 2,000 British civil servants who had no mental health problems when the study began in 1991, and whose average age was 47. About six years later, 66 cases of major depression were found in the workers after they received mental health screenings.

Men and women who worked more than 11-hour days had a more than twofold increased risk of depression, compared to public employees who spent less than eight hours at the office.

The civil servants who were more likely to become depressed were typically younger females in lower job grades who used alcohol moderately and also had a chronic disease.

The research appears in the online journal PLoS ONE.

Long Hours and Depression

A variety of genetic, physical, and emotional factors can make a person vulnerable to depression. At the workplace, the prolonged stress felt by people with long hours is one of the contributing factors to depression.

"Long working hours are likely to be related to less time to relax and less sleep," says study researcher Marianna Virtanen, PhD. She is a team leader of the Work and Mental Health team at the Finnish Institute of Occupational Health in Helsinki.

"It is also possible that excessive working hours result in problems with close relationships, which in turn, may trigger depression," Virtanen says.

The current economic climate has millions of people working extremely long hours -- or holding two or three jobs just to make ends meet. Many of us are working too much. So how can you tell if all those hours are affecting your mood?

Some warning signs for depression include trouble sleeping, feeling stressed, being irritable and dissatisfied, or lacking pleasure in those things that usually make you happy. You may also make more mistakes on the job, or have trouble getting organized or concentrating.

Workaholics are not immune to depression, but Virtanen suspects it might take them longer to develop depression because they probably find their jobs more rewarding than people who may be forced to put in longer hours.

Although this research was done in the 1990s, these days technology tethers us even closer to our jobs. "Work is no longer so much tied to time and place," Virtanen says. "This may make some people feel highly attached to their work tasks outside of their usual working hours."

Although the study only looked at public employees in white-collar jobs, it's unclear if similar results would be found in blue-collar or private-sector workers.

Better Work-Life Balance

Of course, working long hours is not the only reason people become depressed, but the study raises awareness that it can play a role, says Randy Auerbach, PhD, who researches depression at McLean Hospital in Belmont, Mass.

Auerbach said the number of cases of depression found were reasonable for this population, and that the researchers did a good job accounting for other factors that may contribute to depression, such as economic status, alcohol use, social support, and gender.

The reality is that employees are often driven to work more to hold on to the job and income they have. If it doesn't seem feasible to cut back on your hours, Auerbach says, then ask yourself, "What can I do to put my mental and physical well-being first?"

Longer work hours could result in less time with your loved ones and less time to invest in your self-care. Sleep often slides, as do plans to exercise and eat healthy foods. Time with family and friends may take a back seat.

Yet these are many of the healthy ways that buffer against stress and let people blow off steam.

"It's important to have periods with less pressure at work and shorter hours," Virtanen says. Her other tips for work-life balance include making a distinction between work and leisure, not skipping your vacation time, and taking care of your health, especially sleep and exercise.